This seems to happen when trying to read a broken device:
Mar 22 18:34:35 hostname systemd[1]: Assertion 'b' failed at ../src/basic/path-util.c:390, function path_compare(). Aborting.
Mar 22 18:34:35 hostname kernel: Buffer I/O error on dev sdb1, logical block 479653, async page read
This seems to happen when trying to read a broken device:
Mar 22 18:34:35 hostname systemd[1]: Assertion 'b' failed at ../src/ basic/path- util.c: 390, function path_compare(). Aborting.
Mar 22 18:34:35 hostname kernel: Buffer I/O error on dev sdb1, logical block 479653, async page read